<?php
function request_post($url = '', $param = '') {
	if (empty($url) || empty($param)) {
		return false;
	}

	$postUrl = $url;
	$curlPost = $param;
	$curl = curl_init();//初始化curl
	curl_setopt($curl, CURLOPT_URL,$postUrl);//抓取指定网页
	curl_setopt($curl, CURLOPT_HEADER, 0);//设置header
	curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);//要求结果为字符串且输出到屏幕上
	curl_setopt($curl, CURLOPT_POST, 1);//post提交方式
	curl_setopt($curl, CURLOPT_POSTFIELDS, $curlPost);
	$data = curl_exec($curl);//运行curl
 
	curl_close($curl);

	return $data;
}

$url = 'https://aip.baidubce.com/oauth/2.0/token';
$post_data['grant_type']       = 'client_credentials';
$post_data['client_id']      = 'CZgqc2Zl6HDjRAex2UZigrKN';
$post_data['client_secret'] = 'Bcprl91ThWO4Mrly0FA3KgIdGD3QBeGm';
$o = "";
foreach ( $post_data as $k => $v )
{
	$o.= "$k=" . urlencode( $v ). "&" ;
}
$post_data = substr($o,0,-1);

$res = request_post($url, $post_data);

var_dump($res);

?>